Mets manager Willie Randolph said Martinez slipped in the bathroom and fell on his hip while he was changing his shirt during a series in Florida in May.
"He's fine. I'm not concerned about it," Randolph said.
Randolph said left-hander Darren Oliver, the team's long reliever, would probably start Monday night against the Pittsburgh Pirates at Shea Stadium if he wasn't used Sunday night in the Subway Series finale against the Yankees.
One of a franchise-record six Mets selected to the NL All-Star team on Sunday, Martinez is 7-4 with a 3.45 ERA and 111 strikeouts in 101 2/3 innings this season.
The three-time Cy Young Award winner said it was an honor to be chosen again, but he wouldn't comment on his health.
If Martinez feels better soon, his turn might only get pushed back a bit to later in the week. If his hip is still bothering him, the Mets, with a big lead in the NL East, could choose to let their ace rest all the way through the All-Star break.
"It's tempting. But Pedro wants the ball, he wants to pitch," Randolph said. "We're not going to put a time frame. Just when he feels good."